This blog post is especially for Nikon users with entry-level DSLR cameras such as Nikon D3200, Nikon D5300 or any other DSLR in the 3000s or 5000s lineup as well as the professional-lever cameras such as the D810. All these Nikon DSLR cameras have the ‘AE-L/AF-L’ button placed on the top right side at the back of the camera, which is indeed a very useful button. Recently one of my friends asked me to write a detailed post explaining the functionality and use of the ‘AE-L/AF-L’ button, so let’s get started with it.
What is the role of AE-L/AF-L button on Nikon DSLR cameras?
The term AE-L stands for Auto Exposure Lock and AF-L stands for Auto Focus Lock. As the names suggest, this button allows you to lock the exposure, focus, and/or both while you are using the camera on one of the automatic modes (Automatic, Program, Shutter-priority, Aperture-priority or any of the scene modes).
Understanding AE-L (Auto Exposure Lock) button on Nikon DSLR cameras
When you are using your camera on one of the automatic modes, the metering sensor of your camera determines the correct exposure of the scene and the appropriate shutter speed, aperture and ISO values are selected by your camera. This is how the exposure is measured by your camera, and it changes as the light in your scene alters.
Using the AE-L button placed at the back of your camera, you can lock the exposure (shutter speed, aperture and ISO values) so that it does not change when the light varies in your scene. For example, you are photographing a flying bird and the background is changing as the bird moves. In order to correctly expose for the bird, simply use this button to lock the exposure and be sure of the fact that the exposure would not change as you move the camera.
Another example: If you are clicking multiple photos to make an HDR image or a panorama, it is really important that the exposure (shutter speed, aperture and ISO values) remain the same in all the photos. Using the AE-L (Auto Exposure Lock) button, you can achieve the same exposure in as many photos you wish to.
You can also use the AE-L button to click beautiful silhouettes. All you have to do is expose for the brightest part of the scene and then press this button to lock the exposure. Now recompose your frame and click the photo in order to capture silhouette effect.
Understanding AF-L (Auto Focus Lock) button on Nikon DSLR cameras
As you move your camera or as the position of the subject in your scene changes, the lens starts hunting for the subject again in order to adjust the focus as you keep the shutter release button half-pressed. This happens if you are using the ‘AF-C’ (continuous focus) mode. One example of such situation is while you are out for wildlife photography tracking birds and as you keep the shutter release button half-pressed, the lens keeps on changing the focus plane. Your camera might sometimes fail to correctly focus in such conditions and you would end up with a bad image.
This is when the AF-L button comes to your rescue, as by pressing the button you can lock the focus and stop the lens from continuously hunting for the focus. When you want the focus to be locked, simply press the button and click as many photos you wish to with the focal plane set to a fixed position. This is only effective when the subject is moving parallel to the camera, making sure that the focal plane does not change. The moment the focal plane changes (the distance between the camera and the subject), the subject start appearing out-of-focus.
One ideal situation when you can use the AF-L button is while clicking panning photos and you know that the distance between the camera and the subject would remain constant. Lock the focus of your lens using this button on the point/position where the subject would be passing by. Now all you would have to do is pan your camera along with the subject and press the shutter release button to click the photo, without making your lens hunt for the focus.
Different AE-L/AF-L button modes
By default, both the camera exposure and the focus gets locked as long as you keep the AE-L/AF-L button pressed. You can modify the behavior of this button by customizing it from the Assign AE-L/AF-L Button option in the menu. Each Nikon camera has its own range of controls that can be assigned to this button. In this post we would be looking at some of the basic modes:
- AE/AF Lock: This is the default mode, the exposure and the focus remains locked till the till press the button. Once you release the button, the auto focus and auto exposure cones into effect again.
- AE Lock Only: Exposure remains locked only as long as you press the button. This does not lock the focus.
- AE Lock (Hold): This allows you to lock the exposure by just pressing the button, no need to press and hold it. Simply press the button again to remove the exposure lock.
- AF Lock Only: Focus remains locked only as long as you press the button. This does not lock the exposure.
- AF-On: Assigning this mode allows the button to control the auto focus of the lens. This means that half-pressing shutter release would not let the lens to focus, instead the AE-L/AF-L button would be assigned this role. This is basically the back-button focusing technique.
This is a great alternative for those who are not yet able to explore the manual mode, or are more comfortable in using the automatic shooting modes. Without worrying much about the technical aspects or doing calculations, you can focus more on the composition of your frame. In the initial days of using the AE-L/AF-L button, you might struggle a bit but trust me, this is extremely helpful in many shooting conditions.
(Featured image from: photo facts)